In each volume, an introductory essay outlines of history of the disciplines under discussion, and describes how changes and innovations in these disciplines have affected our lives. The biographies that follow are organized in an A-Z format: each biography is divided into a ""life"" section describing the individual's life and influences and a ""legacy"" section summarizing the impact of that individual's work throughout history. These biographies cover a diverse group of men and women from around the globe and throughout history.Franklin Delano Roosevelt, Mao Tse-tung and Genghis Kha